Thank you for the continued help. Here is the entire console log with the unminified 3.5.1

jscript_jquery.js:10353 Uncaught TypeError: url.indexOf is not a function
at jQuery.fn.init.jQuery.fn.load (jscript_jquery.js:10353)
at jscript_menu_conf.js:91
jQuery.fn.load @ jscript_jquery.js:10353
(anonymous) @ jscript_menu_conf.js:91
jquery.checkout_one.js?1618668915:54 setFormSubmitButton, payment-module: null
jquery.checkout_one.js?1618668915:54 Showing "confirm"
jquery.checkout_one.js?1618668915:54 Setting orderConfirmed (0), submitter (null)
jquery.checkout_one.js?1618668915:54 jQuery version: 3.5.1
jquery.checkout_one.js?1618668915:54 saveCustomerInfo, starts ...
index.php?main_page=checkout_one:56 {cache: false, type: "POST", traditional: true, dataType: "json", timeout: 5000,##…}
jquery.checkout_one.js?1618668915:998 Uncaught TypeError: Cannot read property 'length' of null
at jquery.checkout_one.js?1618668915:998
at fire (jscript_jquery.js:3496)
at Object.fireWith [as resolveWith] (jscript_jquery.js:3626)
at Object.deferred.<computed> [as resolve] (jscript_jquery.js:3964)
at Object.success (index.php?main_page=checkout_one:64)
at fire (jscript_jquery.js:3496)
at Object.fireWith [as resolveWith] (jscript_jquery.js:3626)
at done (jscript_jquery.js:9786)
at XMLHttpRequest.<anonymous> (jscript_jquery.js:10047)
(anonymous) @ jquery.checkout_one.js?1618668915:998
fire @ jscript_jquery.js:3496
fireWith @ jscript_jquery.js:3626
deferred.<computed> @ jscript_jquery.js:3964
success @ index.php?main_page=checkout_one:64
fire @ jscript_jquery.js:3496
fireWith @ jscript_jquery.js:3626
done @ jscript_jquery.js:9786
(anonymous) @ jscript_jquery.js:10047
load (async)
send @ jscript_jquery.js:10066
ajax @ jscript_jquery.js:9682
(anonymous) @ index.php?main_page=checkout_one:76
Deferred @ jscript_jquery.js:3979
zcJS.ajax @ index.php?main_page=checkout_one:42
saveCustomerInfo @ jquery.checkout_one.js?1618668915:976
saveBilling @ jquery.checkout_one.js?1618668915:734
dispatch @ jscript_jquery.js:5429
elemData.handle @ jscript_jquery.js:5233